why people don't like showing their wallet is because from there somebody can see how much bitcoin you own.
This could be why people aren't comfortable sharing their addresses, because they don't want their net earnings
available for everyone to see.
Once a hacker had sought how many btc wagered or how many btc you have balance, you could be their next target.
Just like in my blockchain, I don't know how does a person known my identification code since I am the only one who have known that.
However since my gmail wasn't hacked, he wasn't able to open my wallet. This is alarming because hackers are desperate to steal money from others.
Hence, protect your wallet. Don't use your main wallet your every transaction so that no one could tend an attention to check your btc balance/wagered.