Look, most of the guys you mention there were brought in mid-season as stop gap measures (Juskowiak is the perfect example, came for what 1.5 months...the Metros didn't spend much money either...). They also didn't cost much. Zizi Roberts is a good player but he's injured. Powell is Jamaican, but he too has been injured. I forgot about Ivanov, but Ivanov had some good games and some bad games, I call him a wash, not a flop. You also forget about the successes for the Euro guys, Molnar..Nowak, Donadoni. These guys brought class to the league. What you have to realize is that in the US we don't have a very big soccer IQ, in terms of the way we play the game, and understand. Having some veterans (and yes, of course cheap talented youngsters) will teach younger players the way the game should be played. I understand the hope that we have these veterans, but I still think it is part of the process.
Two things. I didn't forget the successes, I wasn't addressing them because you commented that there hadn't been many failures. Sure there have been successes, but the league has had much more trouble finding them in recent years compared to in the beginning. Powell isn't Jamaican. He was born in Lambeth, England, acquired Jamaican nationality to play for the national team, but spent his whole career in England. This is fair. I'd just rather the veterans with the big soccer IQs be coaches rather than expensive players.
Ivanov never had a good game - he was just plain terrible. Slow and pretty horrible in the air for someone his size. He was a complete let down in DC for as much as Ray pumped him up. Hell, he would have been a let down for a sixth round draft pick.
I always wondered why MLS has never signed a Greek player. Especially with the large Hellenic concentrations in Chicago, Boston and New York. Euro 2004 squad member Vasilis Tsiartas was without a team up until recently. He would have been a good find. An experienced and talented Euro and one who would bring people in to the stadiums.
Look at the best players over the last few years - Nowak, Preki, Stoichkov, Herzog (until Sampson anyways), its not a retirement league, but the pace here can be conducive to getting a few more years out of a player if his ball skills are good. Take away those old imports and MLS would have been much poorer over its existence (and there's plenty more example). Not every 30-something import is a Steve Howey or Darryl Powell.