this industry works a lot on superstions more than talent, no music director wants to risk a "lucky" combination with a singer to deliver a flop.
When Alka Yagnik was ruling the roost, there was Sadhna Sargam and Anuradha Paudwal around, who were infinetly more talented and melodious than Alka, however they would be getting only bits and pieces of the work over lucky Alka, and yes Anuradha Paudwal opted to sing only if the music rights was offered to t-series, thus eliminating herself from the music scene.
anyways, to say Vaishali has a bleak future would bbe wrong, maybe yes the hindi film music world may not give her whats her due, but Marathi music, has a very great legacy ........ no wonder people like Sonu Nigam, Shankar Mahadevan etc. are associated with marathi music scene ....... ex-SRGMP gems like Bela, Prajakta Joshi, Hrishikesh Ranade etc. are linked with promoting quality music, I happened to chance upon this information when a colleague of mine took me along with him to such a musical evening .... it was so heartning to know people out there are still into some real good music and its no wonder that currently Zee Marathi's Lil Champs is creating waves with the awesome quality of tiny tot singers there ....... Good Music in general in Mumbai definetly has a bright future.