The simple answer is that Gleevec got there first. When Gleevec first came it it was obvious almost immediately that it was better than anything else available by several orders of magnitude. It therefore became the 'gold standard' treatment remarkably quickly.
With the second generation TKIs you have to measure them against G which has an excellent track record as a first line drug. To shift it from its place will need a large body of evidence over a long period of time in order to be confident (to the level of not worrying about being sued) that it will indeed have long term results which are as good or better than G and a side effects profile as good or better.
There are trials underway at present using Sprycel as a first line drug and I'm sure BMS are doing everything they can to try to speed the process and take market share from Novartis, but it's going to take some time to build a good enough case to topple the mighty G.
Sorry to hear about your side effects.