Blackhawks-I hope that I was not unclear in my argument: I am not arguing for HS soccer over club soccer. I believe that the two are complimentary and, as "dglade" says, not mutually exclusive.
As far as someone getting noticed by a DI coach based more on their HS accomplishments vs their club team, there are a few. One that I can think of off-hand is Settle. As far as I'm aware, he never played on a club team that went to regionals and was a bit of a club hopper. However, he got noticed by Wisconsin because he was a NSCAA All-American and Parade All-American based on his HS play. As you may know, he eventually went on to play and be Wisconsin's starting goalkeeper.
When you bring up Schilling and Arpey and how they got recruited, it is important to recognize how DI soccer recruiting has evolved over the years.
Initially, college coaches primarily recruited by going to look at club and HS teams play (this is going way back). This was when Iowa players were never seen because coaches never came to Iowa. With limited resources and time, college coaches concentrated on particular clubs and high school's that perennially had good players. At this time, coaches also went to HS state tournaments (of states with top players). Regionals and nationals were of little use because they were only played at U-16 and U-19. Obviously, U-16 was too young and the teams at U-19 were too old.
ODP developed and became a recruiting bananza. College coaches could use ODP to see the best players from each state and develop relationships with them without having to worry about NCAA recruiting restrictions (NCAA regulations have an exemption for olympic development programs in any sport). However, many "top" soccer states' top players still did not participate in ODP. This was because ODP conflicted with their club team schedule and they were already getting seen. Also, at this time, large national invite tournaments started to take hold and regionals expanded to include U-17 and U-18. So, recruiting at this time started to take more the form of ODP, regionals, and the big invite tournaments.
With the exception of ODP, Iowans struggled under this format. This was because at both regionals and the big invite tournaments, DI coaches didn't show up until after the group stage or, if they did, they would seen an Iowa team on the schedule and, biases being what they are, go to a different match.
The success of the big invite tournaments bred a new type of tournament: the "showcase." Also, the invite tournament, and its critical mass of top club teams, helped create the want for what I would call semi-permanent tournaments. These new "leagues", such as MRL, became another place that a coach could go and see a number of games/players. All of these tournaments and leagues catered to the needs of college coaches from DI to DIII to NAIA.
However, DI coaches started to look at what other sports were doing (i.e., basketball)--and were probably sick of spending their Thanksgiving, Christmas, etc. on the soccer field--and recognized that camps were the best way to recruit. They recognized that if a prospect was serious about their school, they would come to their camp. Also, once a prospect is on campus, all NCAA contact rules go out the window. Today, top DI schools run multiple camps including two or three day "college prep" camps with the sole intent of identifing and recruiting prospects. Often, these camps are staffed by lower level coaches (lower level DI assistants, DII and DIII, NAIA, and NJCAA) looking to pick up prospects that, for whatever reason, the primary school does not want. Also, there has been the development of independant camps staffed by college assistants whose sole objective is player identification. (At all of these camps, coaches don't just "happen to be" there.)
Prior to the development of the academy system, top DI coaches primarily recruited via camps, regionals, and top level tournaments (whether showcase or traditional structure). In the latter two, identification of a potential prospect was left to assistants.
The development of the academy system really knocks out the importance of regionals, tournaments, and MRL. Obviously, with limited resources, DI coaches are going to go where the largest critical mass of top players are. Since the top clubs are no longer at regionals, MRL, or tournaments, DI coaches are less likely to be there. They are only going to be there to see non-academy players that have already been identified as a prospect through other avenues.
Which brings up the question: What are the other avenues for Iowans? The answer is build up enough accolades that they take a look. In today's world, club accolades probably mean that you have to win regionals (a lot more possible now that the best teams are no longer entered). ODP: win nationals. HS allows you to build a number of accolades: all-State, all-Tournament, Player of the Year, etc. You then have to be proactive at the institutions you might want to go to. And finally, once you get some contact, go to their camp.
Since you have to be proactive--which means you have to be selective--this all builds with what DMMenace said. Which is to say, you have to be proactive with the schools you are interested in going to and getting a degree from in the area of study you are interested in.