Not sure my two cents is worth much but here goes. I think we have to realize that Lipton, Red Rose, Tetley and other "blended" teabag merchants are providing a product. It may not be a product we all like but nonetheless it is a product just like the best Long Jing or Mao Feng or Ti Guan Yi or any other tea manufacturer you may happen to like.
Lipton has changed its blend several times for several reasons. The main reason is the availability from year to year of the tea leaves available to Lipton in the quantities needed to produce its product. With the Sunami last growing season it devestated much of Sri Lankas tea crop and the ensuing unusually dry season didn't help either for India's tea crop. This meant that Lipton and others had to buy their bulk tea elsewhere and it meant that their "taste testers" had to blend various harvests together to provide the same level of taste and quality that is known as the Lipton brand.
Having said all this I can drink any tea including Lipton when desperate enough. I give Lipton Red Rose Tetley and others high marks for consistency year to year. You may not like it and that's fine but realize they produce a product that is "standardized" year to year which is pretty amazing when you realize the scale on which they produce.
For me personally I prefer none blended teas particularly from the high mountain regions of Taiwan, The West Lake Region and Yunnan and Fujian Provinces of China but that's just me. I will tell you the 'consitency' of tea from these regions vary from year to year just like wine.
Just a side note ( and I may start another string about this ) tea has never recovered its "king" status in the US since the war of 1812. Coffee has remained king since then and little doubt it will remain so for sometime to come. But tea is a more gentile and subtle beverage that comes to us when we are older and perhaps a bit wiser to understand that "in your face" isn't always the way to go.