Different HTTP response from inspector HTML

I am trying to get data for the following website using requests and Scrapy Selector.

import requests
from scrapy import Selector

url="https://seekingalpha.com/article/4312816-exxon-mobil-dividend-problems"
headers = {'user-agent': 'AppleWebKit/537.36'}
req = requests.get(url, headers=headers)
sel = Selector(text=req.text)

I could extract the text body but when tried to get the XPath for comments,

I noticed that the HTML returned from requests is different from the inspector, therefore selecting the class='b-b' like,

sel.xpath("//div[@class='b-b']")

returns an empty list in Python. It seems that I'm missing something or the HTML is partially hidden from the bots.

After view(response) I found out the following is rendered, My Questions

1. Why the same HTML cannot be seen in the HTTP response?
2. How to get the comments data using XPath expressions for this page