A lot of the more popular wallets (such as Electrum) are open source and developed by people who truly wanted to see Crypto succeed and wanted to improve accessibility and usability. They discovered crypto early, and found a way to build/improve on it. Developers of wallets like these generally have good intentions and just want to better Crypto as a whole.
When a coin dev releases a wallet for their own coin, they want the coin to succeed as they probably hold a significant stake in that said coin.
Other wallets aim to generate revenue for themselves through affiliate links, ads, etc. An example of this is coinami or blockchain.info. They have a built in "currency exchange" feature where you can trade altcoins using shapeshift and/or changelly, and they make a % of the exchange fee.
And finally, yes there are many wallets out their that are scams and/or contain malware aiming to steal your coins. A very recent example of this is ElectrumPro, which was basically a ripoff of Electrum but packaged with malware. This is why its important to use a wallet that is open source and secure.
Good analysis! I think that you emphasize in general lines with what intention were created the Wallets that we know today.
My attention was drawn to the fact that you pointed out the blockchain.info wallet. Recently, I created a Wallet on the platform and I hope to make good use of it. As a new user I agreed to carry out a survey and I answered it without any concern because I understand due to the series of questions that it was about getting to know the client, improving the product and knowing the client's satisfaction.
Today we are talking about the protection of user data in all scenarios, the topic is trending and there are even several projects that have been working according to the data of the users, taking advantage of the blockchain technology, the innovation, the advancement of technology, as well as solving some problems of today's world and a lot of things.
When we participate in the internet in a public way, anybody can access our data and measure us, create statistics, etc. is my knowledge when we do it public I do not have any knowledge of our private data.