Its not a case of webmasters ignoring a possible source of website traffic its more of a case of msn not taking a) an interest in improving search and b) showing no signs of supporting the webmaster community.
Be honest, the live serps are at best dire. They are next to useless. They have sites missing all over the index and junk ranking left right and centre.
In my office the default page for all staff computers is msn. Yet every staff member uses google to search despite the msn search box being at the top of the page. Thats because the staff know they wont get the answers they want and need to "google it" to get results!
We all want msn to improve and be a real contender against googles hold, we need a serious alternative, its good for search quality but msn are not it.
Currently, Its like msn have given up on search all together and thats why interest in this forum reflects that. If they improve search then maybe webmasters will start showing an interest and be more bothered about traffic from them