I don't think they're necessarily bad. Just watch the sodium content, the carb or fat content if you're concerned about any of the two specifically. These frozen meals don't satiate enough in my opinion, but some days you come back from work really tired, they can save your diet and prevent an otherwise sure binge...
It's not just about nutritional factors, sometimes it's about psychology too... =)
Besides these ready-to-eat meals, you should find some spices or recipes that without adding too many calories give you flavor (it doesn't have to be grilled meat or steamed veggies every day!). For example I love curry and it has very few calories. Try marinating things, etc.
Yo-yo dieter, female, height: 5' 4.5"
07/19/10: 187 lb
12/16/10: 165.2 lb
04/29/12: 202.5 lb
Current: 202.5 lb
Goal #1: 185 lb by 06/10/2012
Goal #2: 170 lb by 08/10/2012
Goal #3: 155 lb 10/13/2012
Final goal: 135 lb